The primary objective of the activities proposed in this application is to provide optical coherence tomography (OCT) Reading Center support to the Comparison of Age Related Macular Degeneration Treatment trials (CATT). The long term goals of this project, that will be accomplished through conduct of specific CATT studies are 1) to identify by OCT those eyes that are most likely to benefit from preventative strategies or treatments designed to prevent vision loss, or improve visual acuity in eyes with AMD, 2) to determine by OCT when treatment is effective or re-treatment is required and 3) to standardize OCT protocols and grading methods in eyes with AMD. The primary objective will be accomplished through the following specific aims: Specific Aim 1: Establish the infrastructure to process OCT images that will be submitted by CATT clinical centers to the CATT OCT Reading Center. Specific Aim 2: Collaborate with the Coordinating Center to establish and implement OCT certification and training programs for CATT clinical study investigators, clinical coordinators and OCT technicians in preparation for CATT. Specific Aim 3: Provide reliable, timely, reproducible, and systematic grading of submitted OCT materials. To achieve these aims, The OCT Reading Center will use a custom, stand-alone web-based system that we have developed to establish and implement secure methods for electronic OCT data submission from the CATT clinical study sites to the CATT OCT Reading Center, and to store and back-up submitted data. We will establish secure methods to transmit data from the OCT Reading Center to the Coordinating Center. The Reading Center will also implement materials and methods for grader, photographer, clinical coordinator and ophthalmologist certification and training, and support study goals as an image resource for recruitment, Study Group meetings, presentations and publications.